According to one known construction, the roller crusher of the type mentioned can be formed with a fixed roller, having its end portions mounted in respective bearings which are lodged in surrounding bearing housings removably attached to a base structure of the equipment. The other roller of the crusher has its end portions also mounted in respective bearings lodged in surrounding bearing housings. However, in this other roller, the two bearing housings are mounted to the base structure of the equipment, so as to allow the other roller, known as moving roller, to be angularly or linearly displaced to and from the fixed roller, permitting not only the adjustment of the operational spacing between the two rollers and the consequent compensation of the wear degree of the two crushing surfaces, but also the displacement of the moving roller to an inoperative dismounting position, spaced apart from the fixed roller.
In another known construction, the roller crusher can have the bearing housings of both rollers mounted to the base structure of the equipment, so as to allow the two rollers to be displaced to and from each other. This type of mounting is being offered to the market by KHD Humbolt Wedag AG.
In these known high pressure crushers, the periodic replacement of the worn out crushing surfaces requires, even with the moving roller or rollers being displaced to an inoperative position, spaced from the other roller, the shafts to be dismounted in relation to the respective end bearings attached in the interior of their bearing housings, which have the form of a surrounding body removably attached to the base structure of the equipment. This dismounting operation is difficult to execute at the installation place of the equipment, in most cases requiring the whole assembly formed by the shaft, crushing shell, end bearings and respective bearing housings to be removed from the equipment and transported to a place in which the replacement of the crushing surface and, eventually, of the bearings, can be adequately and safely carried out.
Taking into account that the assembly defined by each of the rollers and respective bearings and bearing housings represents a large weight, corresponding to a preponderant part of the weight of the equipment as a whole, the operations of dismounting, carrying and remounting the roller assemblies require special cares, which are complex, time-consuming and, consequently, expensive.
Further from the dismounting problems above mentioned, it should be noted that independent bearing housings for each roller allows one end of the shaft of each roller to move independently from the other end, which can result in non-axially aligned and in non-parallel bearings and in skewing of the two shafts, making the process harder to control.